fix: replace deprecated datetime.utcnow() with datetime.now(tz=timezone.utc)

[NIK-TIGER-BILL]

Summary

datetime.utcnow() was deprecated in Python 3.12 and emits a DeprecationWarning at runtime. This PR replaces all occurrences in the memory module with the timezone-aware equivalent datetime.now(tz=timezone.utc).

Changes

Source files (4 files, 9 call sites)

• memory/storage/lancedb_storage.py — 4 calls replaced
• memory/encoding_flow.py — 1 call replaced
• memory/types.py — 2 default_factory + 1 call replaced
• memory/unified_memory.py — 1 call replaced

Test files

• tests/memory/test_unified_memory.py — 5 calls replaced (keeps tests consistent with source)

Why this matters

On Python 3.12+, every call to datetime.utcnow() emits:

DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal
in a future version. Use timezone-aware objects to represent datetimes in UTC:
datetime.datetime.now(datetime.timezone.utc)

The replacement is a drop-in equivalent — datetime.now(tz=timezone.utc) returns a timezone-aware UTC datetime. The Field(default_factory=...) entries in types.py use a lambda wrapper since datetime.now requires a keyword argument.

Testing

• All replaced calls are semantically equivalent
• Existing test suite updated to use timezone-aware datetimes

---

Note

Low Risk
Low risk mechanical change replacing datetime.utcnow() with datetime.now(tz=timezone.utc); main risk is subtle behavior differences when mixing naive vs aware datetimes in existing stored records.

Overview
Replaces deprecated datetime.utcnow() usages in the memory module with timezone-aware UTC timestamps via datetime.now(tz=timezone.utc).

This updates memory record defaults (created_at, last_accessed), scoring recency calculations, and LanceDB storage timestamp creation/touching/parsing to consistently operate in UTC, and adjusts unit tests to use timezone-aware datetimes.

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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Naive/aware datetime subtraction causes TypeError on pre-existing data

High Severity

compute_composite_score now subtracts record.created_at from datetime.now(tz=timezone.utc) (timezone-aware), but _parse_dt in lancedb_storage.py can still return naive datetimes. When val is a datetime instance without tzinfo (line 271–272), it's returned as-is. When val is a string from pre-existing data stored via datetime.utcnow().isoformat() (no timezone suffix), fromisoformat also returns a naive datetime. Subtracting naive from aware raises TypeError at runtime, breaking recall for any data written before this change.

Additional Locations (1)

• lib/crewai/src/crewai/memory/storage/lancedb_storage.py#L270-L272

 

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